Question: Suppose a parallelogram has base length $3 \text{ }$ and height $7 \text{ }$. What is the parallelogram's area?
Explanation: ${b = 3\text{ }}$ ${h = 7\text{ }}$ $21$ By moving a slice of the parallelogram, we can see that its area is equal to that of a rectangle with the same base and height. area of rectangle $ = b \times h$ $A = 3 \times 7 = 21$